In recent years, as a display device for displaying various information, an electrophoretic display device for displaying information by controlling a position of electrophoretic particles (charged migration particles) or a liquid crystal display device for displaying information by applying a voltage to a liquid crystal has received attention.
These display devices are constituted by a matrix of pixels each at which gradation display can be effected.
FIGS. 12(a) and 12(b) are respectively a sectional view showing an example of a structure of a conventional electrophoretic display device described in Japanese Laid-Open Patent Application (JP-A) No. 2000-258805. This electrophoretic display device includes a pair of substrates 21a and 21b provided with electrodes 24a and 24b, respectively. In a spacing between the substrates 21a and 21b, a dispersion liquid 22 and electrophoretic particles 23 are disposed. The dispersion liquid 22 and the electrophoretic particles 23 have been colored different colors. As shown in FIG. 12(a), in the case where the electrophoretic particles 23 are attracted to the electrode 24a side, the color (e.g., black) of the dispersion liquid 22 is visually identified as the color of the pixels. On the other hand, as shown in FIG. 12(b), in the case where the electrophoretic particles 23 are attracted to the electrode 24b side, the color (e.g., white) of the electrophoretic particles 23 is visually identified as the color of the pixels. Further, in the case where the electrophoretic particles 23 are stopped in an intermediary portion between the substrates 21a and 21b, a halftone is displayed.
Although there arises no particular problem in the case where voltages at adjacent pixels (pixels A and B) are equal to each other as shown in FIGS. 12(a) and 12(b) or provides a small difference therebetween, in the case where the voltage difference between the adjacent pixels is larger as shown in FIG. 13, arrangement of the electrophoretic particles at a boundary portion C between the adjacent pixels are disordered by an electric field interference between the adjacent pixels. As a result, an original gradation cannot be provided to impair a display quality in some cases.